EP 1374392 B1 20060125 - AMPLIFYING CIRCUIT
Title (en)
AMPLIFYING CIRCUIT
Title (de)
VERSTÄRKERSCHALTUNG
Title (fr)
MONTAGE AMPLIFICATEUR
Publication
Application
Priority
EP 0103410 W 20010326
Abstract (en)
[origin: WO02078177A1] In signal sources with high impedance, generally a capacitive signal source , such as capacitor microphone capsules, amplifying circuits are generally used which, along with the actual amplifier having a high-resistance, non-inverting input, also comprise means for coupling signals and for determining operating points. In order to adjust the operating point of the signal source and the amplifier, separate bias sources are provided which are respectively coupled to the signal source or the non-inverted input of the amplifier via a mutual impedance. At least one coupling capacitance is situated in the signal path between the signal source and the non-inverting input of the amplifier. In order to increase noise considerably using one such amplifying circuit, without the disadvantage of very high idle times, the mutual impedances are formed from a non-linear resistance (D1, D2 or D3, D4) and an ohmic resistance (R3 or R4) respectively connected in series thereto. Furthermore, the output signal (S2) of the amplifier (IC1) or a signal derived therefrom is coupled back to the mutual impedances (D1, D2, R3 or D3, D4, R4) via a second or third coupling capacitance (C3 or C4).
IPC 8 full level
H03F 1/34 (2006.01); H03F 1/56 (2006.01); H03F 3/181 (2006.01)
CPC (source: EP US)
H03F 1/56 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
WO 02078177 A1 20021003; AT E316711 T1 20060215; DE 50108798 D1 20060413; DK 1374392 T3 20060522; EP 1374392 A1 20040102; EP 1374392 B1 20060125; JP 2004527169 A 20040902; JP 4031710 B2 20080109; US 2004131210 A1 20040708; US 6812788 B2 20041102
DOCDB simple family (application)
EP 0103410 W 20010326; AT 01929456 T 20010326; DE 50108798 T 20010326; DK 01929456 T 20010326; EP 01929456 A 20010326; JP 2002576095 A 20010326; US 47288704 A 20040309